Is your cell phone ringtone-ing off the vestigial hook? The interruptions may be annoying. But for people with depression, getting a call can help them feel better—especially when they are in the midst of a low day. And therapists often have no way of knowing when their patients are stuck at home in a dark mood.

So researchers at Northwestern University hope to get smart phones to help. They’re developing an app that could monitor the frequency of a person's phone calls, texts and emails. [Michelle Nicole Burns et al., "Harnessing Context Sensing to Develop a Mobile Intervention for Depression", Journal of Medical Internet Research]

Called Mobilyze!, the app can also tap into the phone's GPS and accelerometer to see if a user has been lying around at home all day. After learning your daily rhythms, the app should be able to notice any changes in behavior or telltale signs of isolation. If it does, it’ll send reminders to connect with other people or do something fun to help lift the gloom.

The Mobilyze! app is still being tested and tweaked. But for many people it could provide the one nagging reminder to call their mother—or brother, or friend—that they really need.

—Katherine Harmon

[The above text is a transcript of this podcast.]